When is a placebo not a placebo?

When you hear the word "placebo," you usually think of a phony medicine or other type of medical care that makes people think they are getting real treatment when they aren't. But can a "placebo" actually help someone get better? The answer, according to a new study, appears to be "yes."

Researchers at the University of Rochester School of Medicine & Dentistry in New York and Stanford University in California studied 46 patients with mild to moderate cases of psoriasis, which causes red, scaly patches of dead skin. For three weeks, the volunteers smeared cream on two patches of psoriasis twice a day. One cream contained a steroid medication known to help alleviate the condition, while the second did not. The volunteers didn't know which was which.

Then the test subjects were divided into three groups. One continued to receive 100 percent of the sterioid at each treatment for the next eight weeks. The second also received a full dose, but only one-quarter to one-half the time. The rest of the time they used a substitute that did not contain any steroid. The third group received the active substance every time but at one-quarter to one-half the full dose.

Among the subjects in Rochester, N.Y., those who received the lower dose had a much greater recurrence rate of their psoriasis. But the recurrence rate was virtually identical among those who got the full dose all the time and those who received it only one-quarter to one-half the time.

The findings, published in the journal Psychosomatic Medicine, suggest that just thinking you are getting something that works may actually have an effect--an idea that has been gaining credence in recent years. It could be because emotions are thought to play a role in psoriasis, which often becomes worse when someone is under stress, by affecting the immune system.

The findings indicate that doctors may be able to maximize benefits and decrease side-effects by combining a placebo with a real drug, the researchers say.

The conclusion here seems ahead of the facts. An equally valid conclusion is that you need a certain amount of the steriod all at once for it to be effective, but that you don't need it as often as currently prescribed. In this interpretation, there is no placebo effect.

Rob, I think grm1 has a point. Even the authors of the article acknowledge in their abstract that one possible explanation of the findings is that full-dose of the steroid given less often is successful at treating the outbreaks.

In general, though, I agree that placebos CAN be effective. However, the degree to which their effective often depends on the degree to which the problem is related to perception. For example, placebo chemotherapy is highly unlikely to treat cancer successfully, whereas placebo pain pills or antidepressants can effect improvements in those conditions. Some may argue that this means that the effects aren't real, but that is a misunderstanding of neuroscience on their parts. If the fundamental problem depends on things going on in the brain, then changing the brain may improve the problem. So, therefore, thinking, which reflects activity in the brain, could have significant effects on the problem. And, in fact, all evidence suggests that this is the case.

So, to what degree is psoriasis also a perception issue? I don't know, but you also suggest an interesting idea: That the belief that you're receiving effective treatments could reduce your stress levels and, thereby, improve any condition worsened by stress.

If a placebo effect were a significant mechanism, the 1/4 strength daily-dosing regimen would have had a similar outcome to the placebo group. What this study suggests is that frequent; low strength steroid cream causes paradoxical worsening of psoriasis. There could easily be a wide number of possible interactions involving the immune system on a molecular level.